/*
 * Copyright 2024 LinQingYing. and contributors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * The use of this source code is governed by the Apache License 2.0,
 * which allows users to freely use, modify, and distribute the code,
 * provided they adhere to the terms of the license.
 *
 * The software is provided "as-is", and the authors are not responsible for
 * any damages or issues arising from its use.
 *
 */

package com.linqingying.cangjie.ide.codeinsight.utils

import com.intellij.codeInsight.lookup.LookupElement
import com.intellij.codeInsight.lookup.LookupElementBuilder
import com.intellij.codeInsight.template.Expression
import com.intellij.codeInsight.template.ExpressionContext
import com.intellij.codeInsight.template.TextResult
import com.intellij.codeInsight.template.impl.TemplateManagerImpl
import com.intellij.psi.impl.source.tree.injected.InjectedLanguageUtil
import org.jetbrains.annotations.Nls


abstract class ChooseValueExpression<in T : Any>(
    lookupItems: Collection<T>,
    defaultItem: T,
    @Nls private val advertisementText: String? = null
) : Expression() {
    protected abstract fun getLookupString(element: T): String
    protected abstract fun getResult(element: T): String

    @Suppress("LeakingThis")
    private val defaultItemString = getLookupString(defaultItem)

    private val lookupItems: Array<LookupElement> = lookupItems.map { suggestion ->
        LookupElementBuilder.create(suggestion, getLookupString(suggestion)).withInsertHandler { context, item ->
            val topLevelEditor = InjectedLanguageUtil.getTopLevelEditor(context.editor)
            TemplateManagerImpl.getTemplateState(topLevelEditor)?.currentVariableRange?.let { range ->
                @Suppress("UNCHECKED_CAST")
                topLevelEditor.document.replaceString(range.startOffset, range.endOffset, getResult(item.`object` as T))
            }
        }
    }.toTypedArray()

    override fun calculateLookupItems(context: ExpressionContext) = if (lookupItems.size > 1) lookupItems else null

    override fun calculateQuickResult(context: ExpressionContext) = calculateResult(context)

    override fun calculateResult(context: ExpressionContext) = TextResult(defaultItemString)

    override fun getAdvertisingText() = advertisementText
}

class ChooseStringExpression(
    suggestions: Collection<String>,
    default: String = suggestions.first(),
    @Nls advertisementText: String? = null
) : ChooseValueExpression<String>(suggestions, default, advertisementText) {
    override fun getLookupString(element: String) = element
    override fun getResult(element: String) = element
}
